Stemming from a StackOverflow question[1] and a conversation with Marc-Andre Lemburg via email, I'm filing this issue without any easy way of confirming it myself.

It seems that the logic in platform.python_implementation() has been obsoleted by a change made in IronPython. As it is now, it checks that the slice, sys.version[:10], is "IronPython". Seemingly due to a change in IronPython, this no longer is a correct condition for checking that the implementation is IronPython.

I'm trying to work with the question author on StackOverflow to provide the relevant debugging information to fix this, but it is taking a while to get responses. Without his repr(sys.version) I can't submit a patch with this issue.

I've also only tagged Python 2.7 since I have no way of knowing if this occurs with Python 3.x or anything earlier.

[1]: http://stackoverflow.com/questions/16545027/ironpython-error-in-url-request?noredirect=1#comment23828551_16545027

I missed the fact that the user gave me the information from sys.version: https://stackoverflow.com/questions/16545027/ironpython-error-in-url-request?noredirect=1#comment23847257_16545027

I'll throw together a failing test with this and run it against 2.7, and the 3.x branches.

Cpython was changed via #8964 to handle this situation.